The invention relates to an electrical contact device for transmitting high electric current, comprised of a cylindrical contact pin or plug or the like, and a spring-loaded jack or socket for receiving the pin, with a plurality of essentially parallel spring-loaded contact elements extending axially on a cylindrical inner wall of the jack.
Such devices frequently present alignment problems, particularly when manipulated with the aid of robots, where the contact pin is not precisely aligned with the spring-loaded jack and consequently cannot be inserted into the jack. This problem also occurs when a plurality of jacks are combined into a single unit, for use with a unitized plurality of pins, where the axial (i.e. transverse) separations between the pins do not precisely match those of the jacks, but it is desired to insert the pins simultaneously into the respective jacks.
An underlying problem to which the invention is directed is to devise a contact device of the type described initially above, wherein the contact pins can be inserted into the spring-loaded contact jacks without problem even if during the insertion the respective pins and jacks are not precisely aligned.
This problem is solved, according to the invention, by a contact device which is distinquished essentially in that, in order to create a conduction path despite large tolerances between the contact pin and contact spring jack, the jack is provided with intermediate spring contact elements between it and an outer sleeve body in which the jack is mounted with spring-loading both axially and radially. It has been demonstrated that when a contact device with this construction is employed a pin can be withdrawn from the spring-loaded jack even when the lead to the pin is shifted to a substantial degree laterally with respect to the axis of the jack. The inner spring-loaded jack which is mounted in practically floating fashion within the outer sleeve body may be shifted into the lateral position necessary for receving the contact pin, without detriment to the current-carrying capability of the pin and jack combination. A lateral displacement of +/-1 mm is readily compensable. Further, the inventive contact device thus enables making a plug connection under electrical load.
The inventive contact device is given a particularly simple structure if the jack outer sleeve body is in the form of a cylinder with one closed end, with spring-loaded contact elements on its cylindrical wall and a spring-loaded contact disc on its base.
In this connection, it has proven particularly advantageous, with respect to both structure and operation, for the outer sleeve body to be comprised of two parts, in particular a cylindrical wall and a separate base which is fastenable to the wall; and for the forward edge of the cylindrical wall (the edge directed away from the base) to be provided with a radially inwardly extending flange for supporting the jack inner contact spring which is acted on by the spring action of the contact spring disc. It is easy to mount the contact spring elements on the cylindrical wall of the outer sleeve body prior to the introduction of the inner contact spring jack and after the fixed mounting of the contact spring disc, which latter mounting occurs by fastening the base to the cylindrical wall inside the outer sleeve body. The radially inwardly extending flange, against which the inner contact spring jack is braced, also serves to isolate the contact device under load, for spark protection purposes.
It has proven convenient to provide an assembly wherein the base of the sleeve body is fastened to the cylindrical wall by a screw thread.
Advantageously, the contact spring disc provided on the base may be in the form of a zig-zag configured star disc.
From a manufacturing standpoint it has proven advantageous to provide an axially elongated ring-shaped groove in the region of the radially inwardly extending flange, this groove serving to accomodate the forward ends of the wire spring segments, which segments are regularly distributed over the inner circumference of the cylindrical wall. Further, it is also advantageous to provide a ring-shaped gap between the cylindrical wall and an axially inwardly projecting member on the base, which base is fastened to the cylindrical wall of the outer sleeve body, this gap serving to accommodate the rear ends of the wire spring segments. Still further, it is advantageous to provide two radially impressed ring-shaped inwardly extending ridges in the sleeve body at an axial distance apart, whereby the wire spring segments rest against these ridges while under elastic bending.
Alternatively, it is also advantageous to provide the outer sleeve body with at least one shallow cylindrical recess in the region of the interior of the cylindrical wall, for accommodating the contact spring elements. In particular, a contact spring mat structure comprising the contact spring elements can thus be accommodated. According to an advantageous variant, each shallow cylindrical ring-shaped recess accommodates a ring-shaped contact strip comprised of a plurality of spring-loaded contact fingers which are bent around by approximately 180.degree. and extend out of the plane of the cross-piece joining them.